Acute meningitis is the infection of the subarachnoid space and cerebrospinal fluid by bacteria that may cause local and systemic inflammatory response.
There is the classic triad of symptoms of fever, neck stiffness and altered level of consciousness.
Other symptoms include chills, myalgia, photophobia, severe headache, focal neurologic symptoms, nausea, vomiting, seizures and some patients may present with rash.

Modify treatment regimen for optimal therapy once culture & susceptibility results are in

* In patients suspected of having pneumococcal meningitis, consider adding Rifampicin if Dexamethasone is also given.◊ Addition of Ampicillin may be considered in patients highly suspicious of L monocytogenes infection.

Considerations for Patients with Diagnostic Gram Stain Results

A presumptive diagnosis may be made based on the results of the CSF Gram stain

Modify treatment regimen for optimal therapy once culture and susceptibility results are available

Empiric therapy in an area of high prevalence of Penicillin-resistant S pneumoniae should consist of a combination of Vancomycin plus a 3rd generation cephalosporin

Vancomycin should never be used alone in the treatment of pneumococcal meningitis

Recommended for meningitis caused by Methicillin-resistant Staphylococcus aureus or coagulase-negative staphylococci and is considered an alternative drug for patients with Penicillin allergy and Methicillin-susceptible Staphylococcus aureus (MSSA) meningitis

Concomitant administration of Dexamethasone results in decreased brain inflammation and poor entry of Vancomycin into the CSF

Consider intrathecal administration in patients not responding to IV administration

Duration of Antibiotic Therapy

Duration of therapy has been based more on tradition than on scientific evidence

Should be started by IV route 10-20 minutes before or at the same time as the first dose of antibiotic

Benefit is uncertain when dexamethasone is administered ≥1 hour after the 1st antibiotic dose

Use in children

Dexamethasone is recommended in previously well and non-immunocompromised infants and children with clinically suspected bacterial meningitis caused by H influenzae and S pneumoniae (eg early focal neurologic signs are present)

Use in adults

Adjunctive Dexamethasone is recommended in previously well and non-immunocompromised adults with clinically suspected or known pneumococcal meningitis

Dexamethasone should be continued only if the CSF Gram stain shows Gram-positive cocci in pairs, chains or scattered singly or if blood or CSF cultures are positive for S pneumoniae

Precautions

By decreasing brain inflammation, Dexamethasone may reduce the penetration of antibiotic into the CSF, particularly Vancomycin, and this may result in delayed sterilization of the CSF

Patients who are given Dexamethasone must be closely monitored for evidence of gastrointestinal (GI) blood loss; addition of histamine-2 antagonists is recommended to decrease the risk of gastrointestinal bleeding

Dosage

Adults: 10 mg IV 6 hourly x 4 days

Infants and children: 0.15 mg/kg/dose IV 6 hourly x 4 days

Agents to Decrease Intracranial Pressure (ICP)

The following agents (except Dexamethasone) have not been studied in clinical trials in patients with meningitis

Dexamethasone

As above

Mannitol

Action: Mannitol is a hyperosmolar agent that makes the intravascular space hyperosmolar to the brain and permits movement of water from brain tissue into the intravascular compartment

Dosage: 1-1.5 g/kg IV given over 15 minutes; may repeat once

High-dose Barbiturates

Eg Phenobarbital

Barbiturates may be considered in patients with continued elevated ICP after other measures have failed

Action: Decreases cerebral metabolic demands and cerebral blood flow

Antihypertensive Agents

May be considered for decreasing ICP

Use with caution as rapid lowering of blood pressure may cause compromise in intracranial perfusion and cause brain injury

Anticonvulsants

Eg Diazepam, Lorazepam

Administer if patient has seizures

Non-Pharmacological Therapy

Elevated Intracranial Pressure (ICP)

Patients with signs of increased intracranial pressure (eg changes in level of consciousness, nonreactive or poorly reactive pupils, ocular movement disorders) and who are comatose or are stuporous may benefit from intracranial pressure monitoring

ICP >20 mmHg should be treated

Consider treating ICP >15 mmHg to avoid larger elevations that can lead to cerebral herniation and brain stem injury

Maneuvers to Decrease Elevated Intracranial Pressure (ICP)

Elevation of head of the bed to maximize venous drainage with minimum compromise of cerebral perfusion

There is a high incidence of candidaemia and a substantial burden of comorbidities among neonates as confirmed in a recent nationwide epidemiologic study of paediatric candidaemia. An increasing proportion of nonalbicans species resistant to fluconazole has also been observed.